Some compounds having a 5-benzyloxymethyl-1,2-isoxazoline moiety have been known to be useful for herbicides. For example, U.S. Pat. No. 4,983,210 discloses, as herbicides, 3-substituted-5-benzyloxymethyl-1,2-isoxazoline, wherein the substituents may be selected from the group consisting of thienyl, alkyl, haloalkyl, cycloalkyl, substituted or unsubstituted phenyl, tetrahydrofuranyl, tetrahydrothiophenyl, pyrolidinyl, furanyl, pyrolyl, pyridyl. Some compounds disclosed in U.S. Pat. No. 4,983,210 showed to have herbicial activity in rapeseed or sunflowers under the upland condition tests in greenhouse. U.S. Pat. No. 5,262,388 also discloses 5-benzyloxymethyl-1,2-isoxazoline derivatives substituted with nitrophenyl group at 3-position. Further, JP No. 09-143,171 discloses 5-benzyloxymethyl-1,2-isoxazoline derivatives substituted with carbonyl moiety at 3-position. 143,171 discloses 5-benzyloxymethyl-1,2-isoxazoline derivatives substituted with carbonyl moiety at 3-position. However, there has been a need for development of the novel agents with the highly herbicidal activity and selectivity in crops.
The present investigation has involved the synthesis of the compounds of the formula I, which have not been ever developed as herbicides and have the improved herbicidal activity and selectivity in crops, particularly in paddy rice.